Following the German invasion of Poland on September 1, 1939, hundreds of thousands of Jews and countless other Polish citizens fled eastward ahead of the German advance. On September 17, under a secret agreement with Germany, Soviet troops occupied eastern Poland, where an estimated 300,000 Jewish refugees accepted Soviet rule as the lesser of two evils and stayed. Some 40,000 Jews continued south into Romania and Hungary or northeast into Lithuania, fearing arrest by either the Nazis or the Soviets, or hoping to emigrate abroad from unoccupied territory.

As news spread of the impending October transfer of Vilna and its environs from Soviet to Lithuanian control, thousands of Jews streamed to the centuries-old center of Jewish culture. Once the new international borders were sealed, crossing into Lithuania became risky, and many who tried were turned back.

“Panic, departures en masse. . . . Throngs are leaving their homes on a dangerous migration to an uncertain future.”

—Diarist Dawid Sierakowiak, Lodz, Poland, September 6, 1939

“Our country had been swallowed up by two greedy and cynical powers, each intent on world domination. Polish Jewry, numbering three and a half million and constituting the largest Jewish community on earth, was now in mortal danger.”